OEM vs Retail Windows keys: myths & facts
Understand the real differences between OEM and Retail Windows licences, activation limits and transfer rules – stop the myths and buy the right key.
Quick summary
- OEM: cheapest, single-machine, phone support needed for transfer.
- Retail: pricier, transferable to new PC or VM, Microsoft chat support.
- Activation & updates work identically; only licence terms differ.
Common myths busted
Myth #1 – OEM keys are illegal for consumers
OEM keys can be legally purchased by individuals in most regions, provided they come from legitimate volume licences. EU law even allows resale once the software is first sold.
Myth #2 – OEM cannot be re-activated after hardware change
Partly true: the licence is “tied” to the first motherboard, but Microsoft support can often re-activate after major repairs. Retail is transferable without phone support.
Myth #3 – OEM keys stop receiving updates
Windows Update treats OEM and Retail identically. You get all security and quality patches.
Legal angle (EU & US)
In the EU, the UsedSoft v. Oracle ruling allows resale of software licences after first sale, even if the EULA says otherwise. In the US, case law is looser, but Microsoft rarely pursues individual buyers. The bigger risk is purchasing non-genuine MSDN or stolen volume keys.
Which should you buy?
Buy OEM if you’re building a PC that won’t change motherboard soon and want the
lowest cost.
Buy Retail if you upgrade hardware often or run Windows in VMs across hosts.